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;;; Chickadee Game Toolkit
;;; Copyright © 2016 David Thompson <davet@gnu.org>
;;;
;;; Chickadee is free software: you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published
;;; by the Free Software Foundation, either version 3 of the License,
;;; or (at your option) any later version.
;;;
;;; Chickadee is distributed in the hope that it will be useful, but
;;; WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;;; General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with this program. If not, see
;;; <http://www.gnu.org/licenses/>.
(define-module (chickadee math vector)
#:use-module (ice-9 format)
#:use-module (rnrs bytevectors)
#:use-module (srfi srfi-9)
#:use-module (srfi srfi-9 gnu)
#:use-module (system foreign)
#:use-module (chickadee math)
#:export (vec2
vec2/polar
vec2?
vec2->pointer
vec2-copy
vec2-copy!
vec2-x
vec2-y
vec2-magnitude
vec2-dot-product
vec2-normalize
set-vec2-x!
set-vec2-y!
vec2-normalize!
vec2-mult!
vec2-add!
vec2-sub!
vec3
vec3?
vec3->pointer
vec3-copy
vec3-copy!
vec3-x
vec3-y
vec3-z
vec3-magnitude
vec3-dot-product
vec3-normalize
set-vec3-x!
set-vec3-y!
vec3-normalize!
vec3-mult!
vec3-add!
vec3-sub!))
(define-record-type <vec2>
(wrap-vec2 bv pointer)
vec2?
(bv unwrap-vec2)
(pointer vec2-pointer set-vec2-pointer!))
(define-record-type <vec3>
(wrap-vec3 bv pointer)
vec3?
(bv unwrap-vec3)
(pointer vec3-pointer set-vec3-pointer!))
(define (vec2->pointer v)
"Return a foreign pointer to V."
;; Create foreign pointer lazily.
(or (vec2-pointer v)
(let ((pointer (bytevector->pointer (unwrap-vec2 v))))
(set-vec2-pointer! v pointer)
pointer)))
(define (vec3->pointer v)
"Return a foreign pointer to V."
;; Create foreign pointer lazily.
(or (vec3-pointer v)
(let ((pointer (bytevector->pointer (unwrap-vec3 v))))
(set-vec3-pointer! v pointer)
pointer)))
(define (make-null-vec2)
(wrap-vec2 (make-f32vector 2) #f))
(define (make-null-vec3)
(wrap-vec3 (make-f32vector 3) #f))
(define-syntax-rule (with-new-vec2 name body ...)
(let ((name (make-null-vec2))) body ... name))
(define-syntax-rule (with-new-vec3 name body ...)
(let ((name (make-null-vec3))) body ... name))
(define-inlinable (vec2-ref v i)
(f32vector-ref (unwrap-vec2 v) i))
(define-inlinable (vec3-ref v i)
(f32vector-ref (unwrap-vec3 v) i))
(define-inlinable (vec2-set! v i x)
(f32vector-set! (unwrap-vec2 v) i x))
(define-inlinable (vec3-set! v i x)
(f32vector-set! (unwrap-vec3 v) i x))
(define-inlinable (vec2 x y)
"Return a new vec2 with coordinates (X, Y)."
(with-new-vec2 v
(vec2-set! v 0 x)
(vec2-set! v 1 y)))
(define-inlinable (vec3 x y z)
(with-new-vec3 v
(vec3-set! v 0 x)
(vec3-set! v 1 y)
(vec3-set! v 2 z)))
(define-inlinable (vec2/polar r theta)
"Return a new vec2 containing the Cartesian representation of the
polar coordinate (R, THETA)."
(vec2 (* r (cos theta)) (* r (sin theta))))
(define-inlinable (vec2-x v)
"Return the x coordinate of the vec2 V."
(vec2-ref v 0))
(define-inlinable (vec3-x v)
"Return the x coordinate of the vec3 V."
(vec3-ref v 0))
(define-inlinable (vec2-y v)
"Return the y coordinate of the vec2 V."
(vec2-ref v 1))
(define-inlinable (vec3-y v)
"Return the y coordinate of the vec3 V."
(vec3-ref v 1))
(define-inlinable (vec3-z v)
"Return the z coordinate of the vec3 V."
(vec3-ref v 2))
(define-inlinable (set-vec2-x! v x)
"Set the x coordinate of the vec2 V to X."
(vec2-set! v 0 x))
(define-inlinable (set-vec3-x! v x)
"Set the x coordinate of the vec3 V to X."
(vec3-set! v 0 x))
(define-inlinable (set-vec2-y! v y)
"Set the y coordinate of the vec2 V to Y."
(vec2-set! v 1 y))
(define-inlinable (set-vec3-y! v y)
"Set the y coordinate of the vec3 V to Y."
(vec3-set! v 1 y))
(define-inlinable (set-vec3-z! v z)
"Set the z coordinate of the vec3 V to Z."
(vec3-set! v 2 z))
(define (display-vec2 v port)
(format port "#<vec2 x: ~f y: ~f>" (vec2-x v) (vec2-y v)))
(set-record-type-printer! <vec2> display-vec2)
(define (display-vec3 v port)
(format port "#<vec3 x: ~f y: ~f z: ~f>" (vec3-x v) (vec3-y v) (vec3-z v)))
(set-record-type-printer! <vec3> display-vec3)
(define (vec2-copy! source-vec2 target-vec2)
"Copy SOURCE-VEC2 to TARGET-VEC2."
(set-vec2-x! target-vec2 (vec2-x source-vec2))
(set-vec2-y! target-vec2 (vec2-y source-vec2)))
(define (vec3-copy! source-vec3 target-vec3)
"Copy SOURCE-VEC3 to TARGET-VEC3."
(set-vec3-x! target-vec3 (vec3-x source-vec3))
(set-vec3-y! target-vec3 (vec3-y source-vec3)))
(define (vec2-copy vec2)
"Return a new vec2 that is a copy of VEC2."
(with-new-vec2 new
(vec2-copy! vec2 new)))
(define (vec3-copy vec3)
"Return a new vec3 that is a copy of VEC3."
(with-new-vec3 new
(vec3-copy! vec3 new)))
(define-inlinable (vec2-magnitude v)
"Return the magnitude of the vec2 V."
(sqrt (+ (square (vec2-x v)) (square (vec2-y v)))))
(define-inlinable (vec3-magnitude v)
"Return the magnitude of the vec3 V."
(sqrt (+ (square (vec3-x v))
(square (vec3-y v))
(square (vec3-z v)))))
(define-inlinable (vec2-dot-product v1 v2)
"Return the dot product of the vec2s V1 and V2."
(+ (* (vec2-x v1) (vec2-x v2))
(* (vec2-y v1) (vec2-y v2))))
(define-inlinable (vec3-dot-product v1 v2)
"Return the dot product of the vec3s V1 and V2."
(+ (* (vec3-x v1) (vec3-x v2))
(* (vec3-y v1) (vec3-y v2))
(* (vec3-z v1) (vec3-z v2))))
(define (vec2-normalize v)
"Return the normalized form of the vec2 V."
(with-new-vec2 new
(vec2-copy! v new)
(vec2-normalize! new)))
(define (vec3-normalize v)
"Return the normalized form of the vec3 V."
(with-new-vec3 new
(vec3-copy! v new)
(vec3-normalize! new)))
(define-inlinable (vec2-normalize! v)
"Normalize the vec2 V in-place."
(unless (and (zero? (vec2-x v)) (zero? (vec2-y v)))
(let ((m (vec2-magnitude v)))
(set-vec2-x! v (/ (vec2-x v) m))
(set-vec2-y! v (/ (vec2-y v) m)))))
(define-inlinable (vec3-normalize! v)
"Normalize the vec3 V in-place."
(unless (and (zero? (vec3-x v))
(zero? (vec3-y v))
(zero? (vec3-z v)))
(let ((m (vec3-magnitude v)))
(set-vec3-x! v (/ (vec3-x v) m))
(set-vec3-y! v (/ (vec3-y v) m))
(set-vec3-z! v (/ (vec3-z v) m)))))
(define-inlinable (vec2-mult! v x)
"Multiply the vec2 V by X, a real number or vec2."
(if (real? x)
(begin
(set-vec2-x! v (* (vec2-x v) x))
(set-vec2-y! v (* (vec2-y v) x)))
(begin
(set-vec2-x! v (* (vec2-x v) (vec2-x x)))
(set-vec2-y! v (* (vec2-y v) (vec2-y x))))))
(define-inlinable (vec3-mult! v x)
"Multiply the vec3 V by X, a real number or vec3."
(if (real? x)
(begin
(set-vec3-x! v (* (vec3-x v) x))
(set-vec3-y! v (* (vec3-y v) x))
(set-vec3-z! v (* (vec3-z v) x)))
(begin
(set-vec3-x! v (* (vec3-x v) (vec3-x x)))
(set-vec3-y! v (* (vec3-y v) (vec3-y x)))
(set-vec3-z! v (* (vec3-z v) (vec3-z x))))))
(define-inlinable (vec2-add! v x)
"Add X, a real number or vec2, to the vec2 V."
(if (real? x)
(begin
(set-vec2-x! v (+ (vec2-x v) x))
(set-vec2-y! v (+ (vec2-y v) x)))
(begin
(set-vec2-x! v (+ (vec2-x v) (vec2-x x)))
(set-vec2-y! v (+ (vec2-y v) (vec2-y x))))))
(define-inlinable (vec3-add! v x)
"Add X, a real number or vec3, to the vec3 V."
(if (real? x)
(begin
(set-vec3-x! v (+ (vec3-x v) x))
(set-vec3-y! v (+ (vec3-y v) x))
(set-vec3-z! v (+ (vec3-z v) x)))
(begin
(set-vec3-x! v (+ (vec3-x v) (vec3-x x)))
(set-vec3-y! v (+ (vec3-y v) (vec3-y x)))
(set-vec3-z! v (+ (vec3-z v) (vec3-z x))))))
(define-inlinable (vec2-sub! v x)
"Subtract X, a real number or vec2, from the vec2 V."
(if (real? x)
(begin
(set-vec2-x! v (- (vec2-x v) x))
(set-vec2-y! v (- (vec2-y v) x)))
(begin
(set-vec2-x! v (- (vec2-x v) (vec2-x x)))
(set-vec2-y! v (- (vec2-y v) (vec2-y x))))))
(define-inlinable (vec3-sub! v x)
"Subtract X, a real number or vec3, from the vec3 V."
(if (real? x)
(begin
(set-vec3-x! v (- (vec3-x v) x))
(set-vec3-y! v (- (vec3-y v) x))
(set-vec3-z! v (- (vec3-z v) x)))
(begin
(set-vec3-x! v (- (vec3-x v) (vec3-x x)))
(set-vec3-y! v (- (vec3-y v) (vec3-y x)))
(set-vec3-z! v (- (vec3-z v) (vec3-z x))))))
;; Reader macro for vectors.
(define (read-vec chr port)
(define (consume-whitespace port)
(when (char-whitespace? (peek-char port))
(read-char port)
(consume-whitespace port)))
(if (eq? (peek-char port) #\()
(read-char port)
(error "expected opening #\\("))
(consume-whitespace port)
(let ((x (read port))
(y (read port)))
(if (eq? (peek-char port) #\))
(begin
(read-char port)
`(vec2 ,x ,y))
(let ((z (read port)))
(consume-whitespace port)
(if (eq? (peek-char port) #\))
(begin
(read-char port)
`(vec3 ,x ,y ,z))
(error "expected terminating #\\)"))))))
(read-hash-extend #\v read-vec)
|
